Lawn mower



March 3, 1936; J. s. CAMPBELL LAWN MOWER Filed March 1, 1955 lNVENTOR 15(7MP5ELA ATTORN EY Patented Mar. 3, 1936 UNITED STATES PATENT oF'FicE LAWN MOWER 2 Claims.

Thisiinve ntion relates to improvements in lawn angers, and it has reference in particular to "a type of construction especially suited to the trimn'ii ri'g of grassalo'n'g the edges of flower b'edsfsidewalks, and the -like, where it'is'drdinarllyrequired that the "grassbe trimmed by means of hand shears; it being the principal object of this invention to provide a device of the above character and for the above purposes, having a grass cutting mechanism of novel construction arranged to cut in a vertical plane parallel with and spaced inwardly a slight distance from the plane of a single ground wheel with which the device is equipped.

Another object of the invention is to provide a grass cutting mechanism including a revolubly driven wheel havinga plurality of radially extended blades for shearing action between two fixed blades, and wherein means is also provided for accurately adjusting the spacing of the latter blades to maintain the desired shearing tension.

Other objects of the invention reside in the details of construction of the various parts; in

' their relationship and in the mode of operation of the device, as will hereinafter be described.

In accomplishing these and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawing, wherein- Fig. l is a side elevation of a lawn edger mechanism embodied by the present invention.

Fig. 2 is a cross sectional view of the same,

' taken substantially on the line 2-2 in Fig. 1.

Fig. 3 is a top, or plan view showing attachment of the handle to the ground wheel.

Fig. 4 is a perspective view of the edger.

Referring more in detail to the drawingdesignates what may be the usual type of traction or ground wheel, as employed for lawn mowers, mounted by a pivot bolt 2 between a pair of straps 3--3' fixed rigidly to and forming an extension part of a handle 4 which, as seen T in Fig. 4, is equipped at its upper end with a handle bar 5.

Formed integral with the wheel and concentric thereof, is an internally toothed ring gear 6 and overlying the gear, at the inside of the wheel, is a cover plate 1. This is disposed between the strap 3 and wheel and has a central hole 100 for passage of the bolt 2 therethrough.

Fixed in the lower portion of the cover plate and extending outwardly and perpendicularly therefrom is a tubular bearing 8 in which a cutter cutter blades 13. These blades'areequallyspaced and of equal length and are so disposed as to pass with shearing action, as the disk revolves,

, between a pair of shear plates |4l5 fixed respectively to the lower ends of supports I6 and I! which are securely attached at their upper ends to a post I8 that is fixed in the upper portion of cover plate I and extends perpendicularly therefrom above the shaft bearing 8.

The support It has a hole 28 which receives the outer end portion of the bearing tube 8. Lock nuts Zl-QZ are threaded onto the tube and are clamped against opposite sides of the strap, thus to hold the strap and also the shear plate l4 rigidly against lateral play. Likewise, the strap I! has a hole in which the outer end portion of shaft 9 is revolubly contained. However, there are nuts 262l keyed on the shaft 9 at opposite sides of the strap to prevent its swinging inwardly or outwardly relative to the cutter wheel and to maintain the relative spacing of the shear blades l4 and [5.

The shear blade, or plate It is riveted or otherwise suitably attached to the lower end of strap l6 and extends downwardly and in a forwardly inclined direction. The shear blade i5 is rigidly mounted by a stud 3!] through its upper end which stud in turn is adjustably fixed in the lower end of strap H by nuts 3i and 32 threaded thereon against opposite sides or the strap. By adjustment of these nuts, the shear blade l5 may be adjusted toward or from blade I4 thus to provide proper shearing action when the blades l3 pass between them. The angular relationship of the blades l3 with respect to the shear blades I4-l5 is such as to cause the shearing action to start at the inner ends of the blades and to progress to their outer ends as the cutter wheel rotates in the direction as indicated by the arrow in Fig. 1.

To prevent rotation of the cover plate on the bolt 2, I have attached a brace bar to the handle and to a lug ll on the plate adjacent the lower edge.

Assuming the device to be so constructed, in use, it is pushed along the ground like the usual lawn mower. The gear Ill operating in mesh with gear 6 drives the cutter shaft 9 and this in turn rotates the cutter wheel l2 causing the blades l3 to pass with shearing action between shear plates I4 and l5 which extend to some extent below the level of the plane on'which the wheel travels.

When wear on the blades or shear plates occurs and the shearing action is impaired, the tension may be taken up by slight inward adjustment of blade 15 by manipulation of nuts 26 and 21 or by an outward adjustment of blade 14 by manipulation of nuts 2| and 22.

This device is especially suited to cutting grass along the edges of sidewalks or along flower beds or close up to Walls.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is- 1. In a lawn edger of the character described, a ground wheel, a handle rotatably mounting the ground wheel, a cover plate applied to the ground wheel at one side thereof, a shaft operatively connected for rotation by the ground wheel, mounted on the cover plate and extending laterally therefrom, a post fixed to the cover plate above the shaft, a pair of supports mounted by the post,

shear blades adjustably mounted on the supports to extend downwardly and in a forwardly inclined position and in close spaced relation, a cutter wheel fixed on the shaft and blades fixed to the cutter wheel to extend radially therefrom and adapted on rotation of the cutter wheel to pass with shearing action against the shear blades.

2. In a lawn edger of the character described, a ground wheel, a handle rotatably mounting the ground wheel, a cover plate applied to the Wheel at one side, a tubular bearing mounted on the cover plate to extend horizontally therefrom at one side of the wheel, a cutter shaft rovolubly contained in the tubular bearing, a gear on the ground wheel and a gear on the cutter shaft meshing therewith, a post fixed to the cover plate and extending horizontally therefrom above the shaft, a pair of supports fixed to the post and extending downwardly therefrom and having openings in their lower portions through which the shaft extends, shear blades fixed in spaced relationship to the lower ends of the supports to extend downwardly and forwardly therefrom, a cutter wheel on the shaft and blades fixed to the cutter wheel and extending radially thereof and adapted on rotation of the cutter wheel to pass between and with shear ing action against the shear blades.

JOHN S. CAMPBELL... 

